For all the latest figures on coronavirus in New Zealand and globally, read more here.

Officials are investigating the first possible community transmission of coronavirus in New Zealand, with the country sitting on alert-level 2 in a new four-tiered warning system.

It comes as many parts of the world move into lockdown - including the UK and large swathes of the United States - and the death toll of the pandemic reaches almost 12,000. There are now almost 300,000 who have been diagnosed with Covid-19 around the world - 90,000 of whom are considered already recovered.

Italy now has more than 53,000 confirmed cases and the world's highest death toll of 4825. It recorded its highest day-to-day jump on Saturday – 793 dead and 6557 cases.

In New Zealand, alert-level 2 means Covid-19 is "contained but risk of community transmission growing" and human contact must be further reduced - over-70s have been told to stay at home and everyone needs to limit domestic travel.

A further 13 positive tests in New Zealand were confirmed on Saturday - the biggest jump in cases in a single day so far - and the country now has 52 cases in total.

Test results are awaited for two possible cases of community transmission – unrelated to overseas travel - in Auckland and Wairarapa.

"At this point, we cannot rule out a risk of community transmission in these cases," Director-General of Health Ashley Bloomfield said yesterday, announcing that the country's Covid-19 tally now sits at 52 confirmed cases.

AP reports that streets, squares and highways are deserted in large parts of the world as curfews and lockdowns multiplied in the face of the rapidly advancing virus that is severely straining many health systems.

Three American states with a combined population of 70 million are moving to restrict residents to their homes to prevent the spread of the new coronavirus. California started on Friday and New York and Illinois were to follow this weekend. Connecticut and Oregon were preparing to do the same.

The United Kingdom - including London - is in lockdown and the death toll there has now reached 233, with 53 new deaths reported in the last 24 hours. NHS England said: "Patients were aged between 41 and 94 years old and all had underlying health conditions."

After Italy and China, Spain now has the third-highest number of infections worldwide. On Saturday it reported almost 5000 new cases in the past day, bringing the total to nearly 25,000. The death toll rose to 1326, up from 1002 Friday.

Italy is struggling, with a median age of the overall population at 45.4 last year – greater than anywhere else in Europe. It is also seven years higher than the median age in China and slightly above that of South Korea.

Figures released on Friday showed the age of Italians dying of Covid-19 averaging out at 78.5. Almost 99 per cent of them were also suffering from at least one pre-existing condition or ailment.

Italy's mortality rate among those infected with the virus is thus a relatively high 8.6 per cent.

"Covid-19 fatalities are hitting older age groups hard," University of Oxford professor Jennifer Dowd noted on Twitter. "Countries with older populations will need to take more aggressive protective measures to stay below the threshold of critical cases that outstrip health system capacities."

Alert level three will be initiated in New Zealand if there's a heightened risk that the disease is not contained and could result in school closures, domestic travel restrictions, more public venue closures, and non face-to-face primary care consultations.

The past 24 hours have again seen the pandemic interrupt everyday life on a scale unprecedented in modern history.

All people aged over 70 – more than half a million people - or anyone with compromised immune systems, are now asked to stay at home. Non-essential domestic travel is discouraged.

"It's not about whether or not you're worried about yourself. It's that you should be worried for those around you, so please take it seriously," Prime Minister Jacinda Ardern said in her first-ever address to the nation.

"This is about saving lives."

As the Prime Minister was talking, drive-through hubs set up for testing coronavirus were being set up around New Zealand, including at Shorecare Northcross on Auckland's North Shore.

On Saturday afternoon, people driving past could see tents set up outside the medical centre with drive-through only access and what appeared to be increased security.

Visitors were being asked not to leave their cars on arrival and to follow directions for traffic management.

"Our staff will take you through a checklist and if you do fit the criteria, we will register your details and make a time for you to come to an isolated section of our Northcross clinic for testing," the centre said on the website.

Yesterday, an Auckland retirement village revealed a person confirmed to be infected with Covid-19 had been staying with one of their residents.

The infected visitor, and his wife, had been staying with a family member, an independent resident living separately to Evelyn Page Retirement Village's main facility.

"The visitor did not visit our village centre or other apartment residents and had minimal contact during his stay with family. He had only a fleeting meeting with one other person outside his family, and that person is aware and is in isolation," manager Jill Clark said.

It was also revealed yesterday that police are ditching drink-drive checkpoints and councils across the country are shutting down libraries, galleries, pools, gyms, and community centres.

Even one of New Zealand's most recognisable tourist attractions, the Hobbiton Movie Set, has closed its gates to prevent Covid-19 spread - leaving hundreds out of work.

The beleaguered hospitality industry breathed a sigh of relief, however. Bars, pubs, clubs, restaurants, and casinos will remain open – for now – with patrons having to sign a guest register at the door and adhere to physical distancing recommendations.

The steps announced by Health Minister David Clark also include configuring electronic gaming machines to allow appropriate physical distancing of at least 1m and limiting table games at a casino to five persons per table.

"These measures are important to protect the health of New Zealanders, which is our number one priority," Clark said.

The Government has already banned gatherings of 500 people outdoors and 100 people indoors.

New Zealand and Singapore have committed to keeping supply chains open and removing any restrictions on essential goods like medical supplies.

Ardern warned that Covid-19 will be in New Zealand for some time. The new restrictions will likely be the new norm for months, she said, and result in "a significant disruption on how we go about our daily lives, but it is necessary to protect lives".

Meanwhile, Te Papa is warning people who visited the museum the same day as passengers from the Ruby Princess cruise ship that they might need to self-isolate.

Three Australian Ruby Princess passengers and a crew member were, on Friday - days after the ship visited New Zealand - confirmed to have Covid-19, the potentially-deadly virus which has killed more than 10,000 worldwide and caused global disruption.

People who visited the Wellington-based museum on Saturday last week - when people from the cruise ship also visited - should consider self-isolating, Te Papa chief executive Courtney Johnston said.

Supermarkets remained packed yesterday, prompting the prime minister to again urge Kiwis not to panic-buy.